Toe iron for safety ski bindings

ABSTRACT

A soleholder member constitutes a coupling link of a four-bar linkage, which is movable from its normal position against the force of a spring and which comprises levers that are pivoted to a carrying plate which constitutes or is pivoted to a baseplate to be secured to the ski. One of the pivot pins which connect the coupling link to the levers and which in the normal position of the toe iron are symmetrically disposed with respect to the longitudinal center line of the toe iron carries an arm which is capable of a limited pivotal movement and which in the normal position of the toe iron assumes an end position in which the free end of said arm overlaps and in one point disposed on the longitudinal center line of the toe iron contacts the free end of another arm, which is connected to the lever that carries the other pivot pin. The spring is held at one end on the carrying plate or on the coupling link and at its other end engages the first-mentioned arm. This arm is provided with a series of spring-connecting means, which are selectively connectable to the spring and which do not influence the initial stress of the spring.

United States Patent 1 3,695,624

Jungkind 1 Oct. 3, 1972 [54] TOE IRON FOR SAFETY SKI BINDINGS [57]ABSTRACT Inventor; Roland J g Fal'chaflt, A soleholder memberconstitutes a coupling link of a y four-bar linkage, which is movablefrom its normal position against the force of a spring and which com-[73 I Asslgnee' 2:22: g 5:22; G-armlsch Pamela prises levers that arepivoted to a carrying plate which y constitutes or is pivoted to abaseplate to be secured [22] Filed: Aug. 4, 1970 to the ski. One of thepivot pins which connect the coupling link to the levers and which inthe normal [211 App, 60347 position of the toe iron are symmetricallydisposed [30] Foreign Application Priorit Data with respect to thelongitudinal center line of the toe iron carries an arm which is capableof a limited 1969 Germany 19 39 843'7 pivotal movement and which in thenormal position of 52] U S Cl 280/11 35 T the toe iron assumes an endposition in which the free [51] lg .Cl A63c.9/00 end of said armoverlaps and in one point disposed on [58] Fie'ld l1 1 3 5 T thelongitudinal center line of the toe iron contacts the s free end ofanother arm, which is connected to the [56] References Cited lever thatcarries the other pivot pin. The spring is held at one end on thecarrying plate or on the UNITED STATES PATENTS coupling link and at itsother end engages the first- 2,858,137 10/1958 Marker ..280/l1.35 Tmentioned arm. This arm is provided with a series of spring-connectingmeans, which are selectively con- FOREIGN PATENTS OR APPLICATIONSnectable to the spring and which do not influence the 1,372,663 8/1964France ..2so/11.35 T m l $9 9f E 9 p g- Primary Examiner-Benjamin HershAssistant ExaminerRobert R. Song Attorney-Fleit, Gipple & Jacobson 7Claims, 3 Drawing Figures TOE IRON FOR SAFETY SKI BINDINGS Thisinvention relates to a toe iron for safety ski bindings, which toe ironcomprises a soleholder member that constitutes a coupling link of afour-bar linkage, which is movable from its normal position against theforce of a spring and which comprises levers that are pivoted to acarrying plate which constitutes or is pivoted to a baseplate secured tothe ski.

Such toe iron has been proposed in a prior application and due to theuse of the four-bar linkage is superior to other known toe irons in thatthe soleholder member moves along an are having a center of curvaturewhich at least approximately coincides with the imaginary axis ofrotation of the skiing boot. As a result, a pivotal movement of thesole-holder member will not cause the skiing boot to perform a movementhaving a component directed toward the tip of the ski under the actionof the force which acts on the heel and forces the boot against the toeiron.

The toe iron described above has the disadvantage, however, that theforce required for a release is variable by a change of the initialstress of the spring. The initial stress of the spring ensures a certainelasticity of the toe iron and a change of this initial stress willresult in an undesired change and in virtually all cases in a reductionof that elasticity. On the other hand, a large effort is required toincrease the stress of the spring. Such adjustment requires a powerscrew or the like.

. It is an object of the present invention so to improve and design atoe iron of the kind described first hereinbefore that the disadvantagesof the toe iron according to the above-mentioned prior application areavoided in a simple manner.

In a toe iron for safety ski bindings, which toe iron comprises asoleholder member that constitutes a coupling link of a four-barlinkage, which is movable from its normal position against the force ofa spring and which comprises levers that are pivoted to acarrying platewhich constitutes or is pivoted to a baseplate to be secured to the ski,the above object is accomplished according to the invention in that oneof the pivot pins which connect the coupling link to the levers andwhich in the normal position of the toe iron are symmetrically disposedwith respect to the longitudinal center line of the toe iron carries anarm which is capable of a limited pivotal movement and which in thenormal position of the toe iron assumes an end position in which thefree end of said arm overlaps and in one point disposed on thelongitudinal center line of the toe iron contacts the free end ofanother arm, which is connected to the lever that carries the otherpivot pin, further, that the spring is held at one end on the carryingplate or on the coupling link and at its other end engages thefirst-mentioned arm, and this arm is provided with a series ofspring-connecting means, which are selectively connectable to the springand which do not influence the initial stress of the spring.

Another advantage of the ski binding according to the invention residesin that it has no screw for stressing a spring so that the set forcerequired for a release of the binding cannot be inadvertently changed,particularly in transit.

The additional arm is suitably immovably held on the lever of thefour-bar linkage. This feature of the invention can easily be realizedif the additional arm is integral with the lever of the four-barlinkage.

In a preferred embodiment of the toe iron according to the invention,the arm which is capable of a limited pivotal movement has a lockingnose, which in the normal position of the toe iron bears on a stopcarried by the lever of the four-bar linkage. If the additional arm isnot immovably held on the other lever of the four-bar linkage, that armmay have a suitable locking nose and the lever may carry a suitablestop.

In a development of the toe iron according to the invention, it hasproved desirable to provide a spring consisting of a helical tensionspring having end hooks extending at an angle of 90 to each other, onehook is hooked on a vertical retaining pin, which is rigid with thecarrying plate, and the arm which is capable of a limited pivotalmovement is provided with spring-connecting means consisting of a numberof holes engagea- He by the other hook of the spring. The holes aresuitably provided on that end face of the arm which is remote from the.spring so that the spring can be quickly and simply relocated by meansof its hook to change the force required for a release of the toe iron.

Another advantage of the toe iron according to the invention resides inthat the spring which has been hooked into one of the holes of the armcapable of a limited pivotal movement can be held in position by a leadseal. For a proof, it may be desirable to use a lead seal to hold thespring in the position which has been selected, e.g., by a dealer forsports articles.

An embodiment of the invention will now be described more fully and byway of example with reference to the drawing, in which FIG. 1 is a topplan view showing a toe iron in its normal position,

FIG. 2 is a top plan view which is similar to that of FIG. 1 but showsthe toe iron with the four-bar linkage swung open and FIG. 3 is a topplan view which is similar to that of FIG. 1 but shows the toe iron setfor another force required for a release.

The toe iron shown in the drawing comprises a soleholder member 1, whichconstitutes a coupling link of a four-bar linkage. That coupling link ispivoted by two pivot pins 2, 3 to levers 4, 5, which are pivoted at 6and 7 to a carrying plate 8. By means which are not significant for theinvention and for this reason are not shown, the carrying plate 8 ispivoted to a baseplate, which is rigid with the ski. The carrying plateis normally held by a locking device against a pivotal movement. Thelocking device is operated by the four-bar linkage in a manner which isnot shown. Only when the four-bar linkage has performed a predeterminedpivotal movement from its normal position is the locking devicedisengaged so that the carrying plate can move relative to the baseplateand the soleholder member can release the toe portion of the skiingboot.

The pivot pin 2 which connects the soleholder member 1 to the lever 4carries an arm 9, which is capable of a limited pivotal movement on thepivot pin. When the toe iron is in its normal position, shown in FIGS. 1and 3, the arm 9 is in its inner end position, in which a nose .10carried by the arm bears on a stop consisting of a step of the lever 4.Another arm 12 is mounted on the pivot pin 3 and non-rotatable relativeto the lever 5. The arrangement of the two arms 9, 12 is such that theirfree end portions overlap and in the normal position of the toe ironcontact at a point which lies on the longitudinal center line of the toeiron. The two pivot pins 2, 3 are symmetrically spaced by the distance afrom the longitudinal center line of the toe iron when the same is inits normal position. V

The arm 9 is held in its inner limiting position under the influence ofa helical tension spring 13. The ends of the helical tension springconsist of hooks 14, 15, which extend at an angle of 90 relative to eachother. The

spring is hooked by the hook 14 to a vertical retaining pin 16, which isrigid with the carrying plate. The arm 9 is formed with a series ofholes 17 for receiving the hook 15. The holes 17 lie on an arc which iscentered on the axis of the retaining'pin 16. The fourbar linkage isheld by the spring in its normal position and can be moved from saidposition only against the force of the spring, as is shown,'e.g., inFIG. 2.

In this toe iron, the force required for a release is not changed by achange of the initial stress of the spring but by a change of the pointwhere the hook 15 of the spring 13 ishooked to the arm 9, whereby theeffort arm through which a moment is exerted by the spring force on thefour-bar linkage is changed. As has been stated, this will not changethe initial stress of the spring because all of the several connectionpoints have the same distance from the retaining pin 16. FIG. 1 showsthe arrangement of the spring providing for a maximum force required fora release whereas FIG. 3 shows the arrangement of the spring for aminimum force required for a release.

FIG. 2 shows the toe iron in a position assumed in response to a forceacting on the soleholder member 1 in a direction which is transverse tothe longitudinal direction of the toe iron and to the right in thedrawing and exceeding the initial stress of the helical tension spring13. The force is transmitted from the soleholder member by means of thelever 4 and the arm 9 to the helical tension spring 13. Upon a decreaseof the force, the helical compression spring returns the four-barlinkage to its normal position shown in FIG. 1. If a force which exceedsthe preset force required for a release acts on the soleholder member 1for more than a very short time, the locking device, not shown, whichnormally holds the carrying plate against a pivotal movement, isdisengaged, as described hereinbefore, so that the carrying plate ispivotally moved relative to the baseplate and the toe portion of theskiing boot is released by the soleholder member. When it is thendesired to restore the toe iron to a condition ready for skiing,it willbe sufficient to swing the carrying plate backby hand. The helicaltensionspring will then automatically return the four-bar linkage to itsnormal position.

a A design may be adopted in which the carrying plate is automaticallyrestored after a safety release of the toe iron. I

A force acting on the soleholder member 1 transversely to thelongitudinal direction of the toe iron and to the left" in FIG. 2 willbe transmitted from the soleholder member by the lever 5, the arm 12 andthe arm 9 to the helical tension spring 13 and will cause the arm 9 toperform a movement relative to the lever 4. In other respects, the toeironresponds just as to the above-described action of a force in theopposite direction. v

wi ii iicilf safety ski bindings comprising a soleholder member, afour-bar linkage, said soleholder member acting as a coupling link ofsaid four-bar linkage, a helical spring, said linkage being movable fromits normal position against the force of the spring, a carrying plate tobe secured to the ski, said linkage having a pair of levers each pivotedto said carrying plate in a laterally spaced relation, said toe.ironfurther comprising a first pivot pin '(2) pivotally connecting the freeend of one of said levers to said coupling link, a second pivot pinpivotally connecting the free end of the other of said levers to saidcoupling link, a first arm (9) pivotally connected to said first pivotpin (2), another arm (12) pivotally connected to said second pivot pin(3), stop means provided on said levers for limiting pivotal movement ofsaid arms with respect to said levers, the free ends of said armsoverlappingly contacting each other at a point disposed on thelongitudinal center line of the toe iron in a normal position thereof, aseries of spring connecting means provided on one of said armspositioned rearwardly of the other of said arms, said spring beingconnected at one end thereof to said carrying plate, the other end ofsaid spring being selectively connectible to one of said series ofconnecting means, whereby effecting variable resisting forces withoutinfluencing the initial stress of said spring.

2. A toe iron according to claim 1, wherein said another arm (12) isimmovably held on the other said lever (5) of the four-bar linkage.

3. A toe iron according to claim 1, wherein said another arm (12) isintegral with the other said lever (5) of the four-bar linkage.

4. A toe iron according to claim 1, wherein said first arm (9) which iscapable of a limited pivotal movement has a locking nose (10), which inthe normal position of the toe iron engages the stop means carried bysaid one of said levers (4) of the four-bar linkage.

5. A toe iron according to claim l, further comprising a retaining pin(16) rigid with the carrying plate,

said spring comprising a helical tension spring having end hooks (14,15)extending at an angle of to each other, one hook (14) being hooked onsaid vertical retaining pin (16), and said spring-connecting meanscomprising a number of holes (17) engageable-by the other hook 15 of thespring (13).

6. A toe iron according to claim 5, wherein the holes lie on an arccentered on said retaining pin (16).

7. A toe iron according to claim 5, wherein that end hook (15) of thespring 13) which extends into one of the holes (17) is provided with alead seal.

1. A toe iron for safety ski bindings comprising a soleholder member, afour-bar linkage, said soleholder member acting as a coupling link ofsaid four-bar linkage, a helical spring, said linkage beiNg movable fromits normal position against the force of the spring, a carrying plate tobe secured to the ski, said linkage having a pair of levers each pivotedto said carrying plate in a laterally spaced relation, said toe ironfurther comprising a first pivot pin (2) pivotally connecting the freeend of one of said levers to said coupling link, a second pivot pinpivotally connecting the free end of the other of said levers to saidcoupling link, a first arm (9) pivotally connected to said first pivotpin (2), another arm (12) pivotally connected to said second pivot pin(3), stop means provided on said levers for limiting pivotal movement ofsaid arms with respect to said levers, the free ends of said armsoverlappingly contacting each other at a point disposed on thelongitudinal center line of the toe iron in a normal position thereof, aseries of spring connecting means provided on one of said armspositioned rearwardly of the other of said arms, said spring beingconnected at one end thereof to said carrying plate, the other end ofsaid spring being selectively connectible to one of said series ofconnecting means, whereby effecting variable resisting forces withoutinfluencing the initial stress of said spring.
 2. A toe iron accordingto claim 1, wherein said another arm (12) is immovably held on the othersaid lever (5) of the four-bar linkage.
 3. A toe iron according to claim1, wherein said another arm (12) is integral with the other said lever(5) of the four-bar linkage.
 4. A toe iron according to claim 1, whereinsaid first arm (9) which is capable of a limited pivotal movement has alocking nose (10), which in the normal position of the toe iron engagesthe stop means carried by said one of said levers (4) of the four-barlinkage.
 5. A toe iron according to claim 1, further comprising aretaining pin (16) rigid with the carrying plate, said spring comprisinga helical tension spring having end hooks (14,15) extending at an angleof 90* to each other, one hook (14) being hooked on said verticalretaining pin (16), and said spring-connecting means comprising a numberof holes (17) engageable by the other hook (15) of the spring (13).
 6. Atoe iron according to claim 5, wherein the holes lie on an arc centeredon said retaining pin (16).
 7. A toe iron according to claim 5, whereinthat end hook (15) of the spring (13) which extends into one of theholes (17) is provided with a lead seal.